Overview of the Proof of a Trivial Consequence

ACL2 Warning [Subsume] in ( DEFTHM TRIVIAL-CONSEQUENCE ...): The previously
added rule ASSOCIATIVITY-OF-APP subsumes the newly proposed :REWRITE
rule TRIVIAL-CONSEQUENCE, in the sense that the old rule rewrites a
more general target. Because the new rule will be tried first, it
may nonetheless find application.